Rate of fire mattered more than accuracy in combat at the time, and smoothbore guns were quicker to reload. Infantry combat typically took place at close range, especially after the Swedish Empire introduced the bayonet charge. Units would generally fire coordinated volleys at enemy formations, and in doing so the accuracy of any particular shot wasn't terribly relevant as it was relatively likely to hit something - but rate of fire was very relevant, as an extra second or two could make the difference between getting routed with a bayonet charge or cutting it down at point-blank before it could strike.